|
|
|
|
|
| Taillandier, Vincent; Wagener, Thibaut; D'Ortenzio, Fabrizio; Mayot, Nicolas; Legoff, Herve; Ras, Josephine; Coppola, Laurent; Pasqueron De Fommervault, Orens; Schmechtig, Catherine; Diamond, Emilie; Bittig, Henry; Lefevre, Dominique; Leymarie, Edouard; Poteau, Antoine; Prieur, Louis. |
| We report on data from an oceanographic cruise, covering western, central and eastern parts of the Mediterranean Sea, on the French research vessel Tethys 2 in May 2015. This cruise was fully dedicated to the maintenance and the metrological verification of a biogeochemical observing system based on a fleet of BGC-Argo floats. During the cruise, a comprehensive data set of parameters sensed by the autonomous network was collected. The measurements include ocean currents, seawater salinity and temperature, and concentrations of inorganic nutrients, dissolved oxygen and chlorophyll pigments. The analytical protocols and data processing methods are detailed, together with a first assessment of the calibration state for all the sensors deployed during the... |
| Tipo: Text |
|
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00677/78943/81333.pdf |
| |
|
|
| Xing, Xiaogang; Claustre, Herve; Blain, Stephane; D'Ortenzio, Fabrizio; Antoine, David; Ras, Josephine; Guinet, Christophe. |
| As the proxy for Chlorophyll a (Chl a) concentration, thousands of fluorescence profiles were measured by instrumented elephant seals in the Kerguelen region (Southern Ocean). For accurate retrieval of Chl a concentrations acquired by in vivo fluorometer, a two-step procedure is applied: 1) A predeployment intercalibration with accurate determination by high performance liquid chromatography (HPLC) analysis, which not only calibrates fluorescence in appropriate Chl a concentration units, but also strongly reduces variability between fluorometers, and 2) a profile-by-profile quenching correction analysis, which effectively eliminates the fluorescence quenching issue at surface around noon, and results in consistent profiles between day and night. The... |
| Tipo: Text |
|
| Ano: 2012 |
URL: https://archimer.ifremer.fr/doc/00248/35965/36927.pdf |
| |
|
|
| Lafond, Augustin; Leblanc, Karine; Queguiner, Bernard; Moriceau, Brivaela; Leynaert, Aude; Cornet, Veronique; Legras, Justine; Ras, Josephine; Parenteau, Marie; Garcia, Nicole; Babin, Marcel; Tremblay, Jean-eric. |
| The Arctic Ocean is particularly affected by climate change, with changes in sea ice cover expected to impact phytoplankton primary production. During the Green Edge expedition, the development of the late spring-early summer diatom bloom was studied in relation with the sea ice retreat by multiple transects across the marginal ice zone. Biogenic silica concentrations and uptake rates were measured. In addition, diatom assemblage structures and their associated carbon biomass were determined, along with taxon-specific contributions to total biogenic silica production using the fluorescent dye PDMPO. Results indicate that a diatom bloom developed in open waters close to the ice edge, following the alleviation of light limitation, and extended 20-30 km... |
| Tipo: Text |
Palavras-chave: Diatoms; Spring bloom; Sea ice; Community composition; Baffin Bay; Arctic. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00615/72752/72021.pdf |
| |
|
|
| Roesler, Collin; Uitz, Julia; Claustre, Herve; Boss, Emmanuel; Xing, Xiaogang; Organelli, Emanuele; Briggs, Nathan; Bricaud, Annick; Schmechtig, Catherine; Poteau, Antoine; D'Ortenzio, Fabrizio; Ras, Josephine; Drapeau, Susan; Haentjens, Nils; Barbieux, Marie. |
| Chlorophyll fluorometers provide the largest in situ global data set for estimating phytoplankton biomass because of their ease of use, size, power consumption, and relatively low price. While in situ chlorophyll a (Chl) fluorescence is proxy for Chl a concentration, and hence phytoplankton biomass, there exist large natural variations in the relationship between in situ fluorescence and extracted Chl a concentration. Despite this large natural variability, we present here a global validation data set for the WET Labs Environmental Characterization Optics (ECO) series chlorophyll fluorometers that suggests a factor of 2 overestimation in the factory calibrated Chl a estimates for this specific manufacturer and series of sensors. We base these results on... |
| Tipo: Text |
|
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00384/49552/50046.pdf |
| |
|
|
| Heimbuerger, Lars-eric; Cossa, Daniel; Marty, Jean-claude; Migon, Christophe; Averty, Bernard; Dufour, Aurelie; Ras, Josephine. |
| Recent findings on the distribution of methylated mercury (MeHgT) in waters have highlighted the importance of organic carbon remineralization on the production of these compounds in the open ocean. Here, we present the first time-series (20 monthly samplings between July 2007 and May 2009) of high-resolution vertical profiles (10-12 depths in a 2350 m water column) of MeHgT distributions in an open ocean environment, the Ligurian Sea (North-western Mediterranean Sea). Concentrations varied within the sub-picomolar range (general mean: 0.30 0.17 pmol L-1, n = 214) with the lowest values at the surface, increasing with depth up to the oxygen minimum zone, and decreasing slowly at greater depth. Concentrations in the surface waters never exceeded 0.15 pmol... |
| Tipo: Text |
|
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00013/12415/9225.pdf |
| |
|
|
|
